Abstract The spread of SARS-CoV-2 and the distribution of cases worldwide followed no clear biogeographic, climatic, or cultural trend. Conversely, the internationally busiest cities in all countries tended to be the hardest hit, suggesting a basic, mathematically neutral pattern of the new coronavirus early dissemination. We tested whether the number of flight passengers per time and the number of international frontiers could explain the number of cases of COVID-19 worldwide by a stepwise regression. Analysis were taken by 22 May 2020, a period when one would claim that early patterns of the pandemic establishment were still detectable, despite of community transmission in various places. The number of passengers arriving in a country and the number of international borders explained significantly 49% of the variance in the distribution of the number of cases of COVID-19, and number of passengers explained significantly 14.2% of data variance for cases per million inhabitants. Ecological neutral theory may explain a considerable part of the early distribution of SARS-CoV-2 and should be taken into consideration to define preventive international actions before a next pandemic.
ABSTRACT Elephant grass (Pennisetum purpureum Schumach) is regarded as a promising feedstock for second generation ethanol production, due to its high cellulose content, biomass production and rapid growth. The yeast Kluyveromyces marxianus CCT 7735 is capable of producing ethanol from agroindustrial residues, such as lignocellulosic biomass. Therefore, this study aimed to establish the optimal conditions for ethanol production by K. marxianus CCT 7735 from elephant grass. Five factors were evaluated: temperature (35-45 ºC), pH (4.5-5.8), agitation (50-150 rpm), cellulase concentration (7.5-22.5 FPU/mL) and elephant grass biomass (8-16% w/v). Enzymatic concentration (22.5 FPU/mL), biomass concentration (16% w/v) and temperature (38 ºC) were the significant optimized factors. K. marxianus CCT 7735 produced a high ethanol concentration (around 45.5 g/L) under these optimized conditions, which is considered feasible in terms of energy requirements in the distillation step.
BACKGROUND: Leg ulcers are characterized as tissue loss in the lower extremities, generally caused by vascular dysfunction. OBJECTIVES: Verify the clinical and epidemiological profiles of the population sample with leg ulcers treated at the health centers of Juiz de Fora (Brazil). MATERIAL AND METHODS: 124 leg-wound patients were evaluated between January 1999 and August 2001 and submitted to a clinical protocol. RESULTS: The mean age was 64 years, with females in the majority (65.3%). The mean family composition was 3.7 persons, and family income was around US$200.00 (86.8%). Venous insufficiency (90.3%), systemic arterial hypertension (54%), obesity (20.2%) and diabetes mellitus (16.1%) were the most frequent events associated with the ulcers. An association of venous insufficiency and arterial hypertension was frequent in 43.7% of the sample, and significant (p<0.01) to predisposition to the ulcers. These were classified as venous (79%), hypertensive (15.4%), mixed and other (5.6%). The ulcers were generally localized in the distal third of legs (90%) and considered large (5 cm) in about 90% of the sample, with means of 8.7 cm and 9.6 cm to vertical and horizontal axes, respectively. The ulcers were accompanied mainly by hyperpigmentation (92.7%), lipodermatosclerosis (68.5%) and varicose veins (66.9%), with a mean duration of 94.2 months and 50% of them recurrent. CONCLUSIONS: The data suggested that leg ulcer is an important chronic disease in the elderly and poor population of Juiz de Fora and region.
FUNDAMENTOS: Úlcera de perna (UP) caracteriza-se por perda do tegumento nas extremidades dos membros inferiores causada geralmente por disfunção vascular. OBJETIVOS: Caracterizar clínica e epidemiologicamente a amostra populacional com UP atendida nos centros de saúde de Juiz de Fora. PACIENTES E MÉTODOS: Submetidos ao protocolo clínico 124 pacientes com UP, de Juiz de Fora e região de janeiro/1999 a agosto/2001. RESULTADOS: A média de idade foi 64 anos, 65,3% do sexo feminino, média de 3,7 indivíduos/família e renda inferior a R$540,00 (86,8%). Associavam-se às úlceras insuficiência venosa (90,3%), hipertensão arterial sistêmica (54%), obesidade (20,2%) e diabetes mellitus (16,1%). A associação insuficiência venosa e hipertensão arterial foi freqüente (43,7%) e significante (p<0.01) para predisposição às úlceras. Foram classificadas como venosas (79%), hipertensivas (15,4%), mistas e outras(5,6%). Acometiam terço distal das pernas (90%), de tamanho grande (5cm) em cerca de 90% da amostra, com médias de 8,7cm e 9,6cm para os eixos vertical e horizontal, respectivamente. Estavam acompanhadas de hipercromia (92,7%), lipodermatoesclerose (68,5%) e varicosidades (66,9%), com duração média de 94,2 meses, e 50% das úlceras eram recidivantes. CONCLUSÕES: Os dados sugerem que a úlcera de perna seja doença crônica significativa na população idosa e de baixa renda de Juiz de Fora e região.